During early childhood, reading books with one’s caregiver (shared book reading) is a valuable means of supporting learning. Yet, there are gaps in our understanding of the influence of shared book reading on young children’s science learning. The current research bridges this gap by examining the pedagogical quality of science books in preschool-aged children’s environments and investigating how such books influence children’s learning and caregivers’ extratextual talk during shared book reading. In Study 1, we coded 60 science books that were readily available in young children’s environments within the United States. The books were designed for English speakers and recommended for preschool-aged children. We coded the books for the extent to which they were Coherent (elaborated on facts presented by providing details, examples, comparisons, etc.) and included Embedded Questions. However, many books were low in Cohesion and Embedded Questions and were of low pedagogical quality. In Study 2, we tested thirty-eight 4- to 5-year-old children (55% female, 76% White) and their caregivers in the Southeastern United States. We assessed the influence of books’ levels of Cohesion and Embedded Questions and of caregivers’ Elaborative extratextual talk during shared book reading on children’s science learning. Children learned more from books high in Cohesion, irrespective of levels of Embedded Questions and caregivers’ Elaborative Talk. Additionally, children learned more from books high in Embedded Questions when caregivers used more...